HTML Parser Home Page

org.htmlparser.beans
Class FilterBean

java.lang.Object
  extended by org.htmlparser.beans.FilterBean
All Implemented Interfaces:
Serializable

public class FilterBean
extends Object
implements Serializable

Extract nodes from a URL using a filter.

 
     FilterBean fb = new FilterBean ("http://cbc.ca");
     fb.setFilters (new NodeFilter[] { new TagNameFilter ("META") });
     fb.setURL ("http://cbc.ca");
     System.out.println (fb.getNodes ().toHtml ());
 
 

See Also:
Serialized Form

Field Summary
protected  NodeFilter[] mFilters
          The filter set.
protected  NodeList mNodes
          The nodes extracted from the URL.
protected  Parser mParser
          The parser used to filter.
protected  PropertyChangeSupport mPropertySupport
          Bound property support.
protected  boolean mRecursive
          The recursion behaviour for elements of the filter array.
static String PROP_CONNECTION_PROPERTY
          Property name in event where the connection changes.
static String PROP_NODES_PROPERTY
          Property name in event where the URL contents changes.
static String PROP_TEXT_PROPERTY
          Property name in event where the URL contents changes.
static String PROP_URL_PROPERTY
          Property name in event where the URL changes.
 
Constructor Summary
FilterBean()
          Create a FilterBean object.
 
Method Summary
 void addPropertyChangeListener(PropertyChangeListener listener)
          Add a PropertyChangeListener to the listener list.
protected  NodeList applyFilters()
          Apply each of the filters.
 URLConnection getConnection()
          Get the current connection.
 NodeFilter[] getFilters()
          Get the current filter set.
 NodeList getNodes()
          Return the nodes of the URL matching the filter.
 Parser getParser()
          Get the parser used to fetch nodes.
 boolean getRecursive()
          Get the current recursion behaviour.
 String getText()
          Convenience method to apply a StringBean to the filter results.
 String getURL()
          Get the current URL.
static void main(String[] args)
          Unit test.
 void removePropertyChangeListener(PropertyChangeListener listener)
          Remove a PropertyChangeListener from the listener list.
 void setConnection(URLConnection connection)
          Set the parser's connection.
 void setFilters(NodeFilter[] filters)
          Set the filters for the bean.
protected  void setNodes()
          Fetch the URL contents and filter it.
 void setParser(Parser parser)
          Set the parser for the bean.
 void setRecursive(boolean recursive)
          Set the recursion behaviour.
 void setURL(String url)
          Set the URL to extract strings from.
protected  void updateNodes(NodeList nodes)
          Assign the Nodes property, firing the property change.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

PROP_NODES_PROPERTY

public static final String PROP_NODES_PROPERTY
Property name in event where the URL contents changes.

See Also:
Constant Field Values

PROP_TEXT_PROPERTY

public static final String PROP_TEXT_PROPERTY
Property name in event where the URL contents changes.

See Also:
Constant Field Values

PROP_URL_PROPERTY

public static final String PROP_URL_PROPERTY
Property name in event where the URL changes.

See Also:
Constant Field Values

PROP_CONNECTION_PROPERTY

public static final String PROP_CONNECTION_PROPERTY
Property name in event where the connection changes.

See Also:
Constant Field Values

mPropertySupport

protected PropertyChangeSupport mPropertySupport
Bound property support.


mParser

protected Parser mParser
The parser used to filter.


mFilters

protected NodeFilter[] mFilters
The filter set.


mNodes

protected NodeList mNodes
The nodes extracted from the URL.


mRecursive

protected boolean mRecursive
The recursion behaviour for elements of the filter array. If true the filters are applied recursively.

See Also:
NodeList.extractAllNodesThatMatch(NodeFilter, boolean).
Constructor Detail

FilterBean

public FilterBean()
Create a FilterBean object.

Method Detail

updateNodes

protected void updateNodes(NodeList nodes)
Assign the Nodes property, firing the property change.

Parameters:
nodes - The new value of the Nodes property.

applyFilters

protected NodeList applyFilters()
                         throws ParserException
Apply each of the filters. The first filter is applied to the output of the parser. Subsequent filters are applied to the output of the prior filter.

Returns:
A list of nodes passed through all filters. If there are no filters, returns the entire page.
Throws:
ParserException - If an encoding change occurs or there is some other problem.

setNodes

protected void setNodes()
Fetch the URL contents and filter it. Only do work if there is a valid parser with it's URL set.


addPropertyChangeListener

public void addPropertyChangeListener(PropertyChangeListener listener)
Add a PropertyChangeListener to the listener list. The listener is registered for all properties.

Parameters:
listener - The PropertyChangeListener to be added.

removePropertyChangeListener

public void removePropertyChangeListener(PropertyChangeListener listener)
Remove a PropertyChangeListener from the listener list. This removes a registered PropertyChangeListener.

Parameters:
listener - The PropertyChangeListener to be removed.

getNodes

public NodeList getNodes()
Return the nodes of the URL matching the filter. This is the primary output of the bean.

Returns:
The nodes from the URL matching the current filter.

getURL

public String getURL()
Get the current URL.

Returns:
The URL from which text has been extracted, or null if this property has not been set yet.

setURL

public void setURL(String url)
Set the URL to extract strings from. The text from the URL will be fetched, which may be expensive, so this property should be set last.

Parameters:
url - The URL that text should be fetched from.

getConnection

public URLConnection getConnection()
Get the current connection.

Returns:
The connection that the parser has or null if it hasn't been set or the parser hasn't been constructed yet.

setConnection

public void setConnection(URLConnection connection)
Set the parser's connection. The text from the URL will be fetched, which may be expensive, so this property should be set last.

Parameters:
connection - New value of property Connection.

getFilters

public NodeFilter[] getFilters()
Get the current filter set.

Returns:
The current filters.

setFilters

public void setFilters(NodeFilter[] filters)
Set the filters for the bean. If the parser has been set, it is reset and the nodes are refetched with the new filters.

Parameters:
filters - The filter set to use.

getParser

public Parser getParser()
Get the parser used to fetch nodes.

Returns:
The parser used by the bean.

setParser

public void setParser(Parser parser)
Set the parser for the bean. The parser is used immediately to fetch the nodes, which for a null filter means all the nodes

Parameters:
parser - The parser to use.

getText

public String getText()
Convenience method to apply a StringBean to the filter results. This may yield duplicate or multiple text elements if the node list contains nodes from two or more levels in the same nested tag heirarchy, but if the node list contains only one tag, it provides access to the text within the node.

Returns:
The textual contents of the nodes that pass through the filter set, as collected by the StringBean.

getRecursive

public boolean getRecursive()
Get the current recursion behaviour.

Returns:
The recursion (applies to children, children's children, etc) behavior currently being used.

setRecursive

public void setRecursive(boolean recursive)
Set the recursion behaviour.

Parameters:
recursive - If true the extractAllNodesThatMatch() call is performed recursively.
See Also:
NodeList.extractAllNodesThatMatch(NodeFilter, boolean).

main

public static void main(String[] args)
Unit test.

Parameters:
args - Pass arg[0] as the URL to process, and optionally a node name for filtering.

© 2005 Derrick Oswald
Jun 10, 2006

HTML Parser is an open source library released under LGPL. SourceForge.net